Recovery from disturbance requires resynchronization of ecosystem nutrient cycles Journal Article


Authors: Rastetter, E. B.; Yanai, R. D.; Thomas, R. Q.; Vadeboncoeur, M. A.; Fahey, T. J.; Fisk, M. C.; Kwiatkowski, B. L.; Hamburg, S. P.
Article Title: Recovery from disturbance requires resynchronization of ecosystem nutrient cycles
Abstract: Nitrogen (N) and phosphorus (P) are tightly cycled in most terrestrial ecosystems, with plant uptake more than 10 times higher than the rate of supply from deposition and weathering. This near-total dependence on recycled nutrients and the stoichiometric constraints on resource use by plants and microbes mean that the two cycles have to be synchronized such that the ratio of N: P in plant uptake, litterfall, and net mineralization are nearly the same. Disturbance can disrupt this synchronization if there is a disproportionate loss of one nutrient relative to the other. We model the resynchronization of N and P cycles following harvest of a northern hardwood forest. In our simulations, nutrient loss in the harvest is small relative to postharvest losses. The low N: P ratio of harvest residue results in a preferential release of P and retention of N. The P release is in excess of plant requirements and P is lost from the active ecosystem cycle through secondary mineral formation and leaching early in succession. Because external P inputs are small, the resynchronization of the N and P cycles later in succession is achieved by a commensurate loss of N. Through succession, the ecosystem undergoes alternating periods of N limitation, then P limitation, and eventually co-limitation as the two cycles resynchronize. However, our simulations indicate that the overall rate and extent of recovery is limited by P unless a mechanism exists either to prevent the P loss early in succession (e.g., P sequestration not stoichiometrically constrained by N) or to increase the P supply to the ecosystem later in succession (e.g., biologically enhanced weathering). Our model provides a heuristic perspective from which to assess the resynchronization among tightly cycled nutrients and the effect of that resynchronization on recovery of ecosystems from disturbance.
Keywords: TERRESTRIAL ECOSYSTEMS; NUTRIENT LIMITATION; DISSOLVED ORGANIC-CARBON; DISTURBANCE; PHOSPHORUS LIMITATION; NORTHERN HARDWOOD FOREST; resource optimization; ATMOSPHERIC DEPOSITION; WHOLE-TREE HARVEST; nitrogen limitation; HUBBARD-BROOK; stable; Nutrient cycles; Co-limitation; STATES; ECOSYSTEM SUCCESSION; ELEMENT-CYCLES; N:P ratio; stoichiometric constraints; terrestrial ecosystem cycling
Journal Title: Ecological applications : a publication of the Ecological Society of America
Volume: 23
Issue: 3
ISSN: 1051-0761; 1051-0761
Publisher: Ecological Society of America  
Publication Place: WASHINGTON; 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA
Date Published: 2013
Start Page: 621
End Page: 642
DOI/URL:
Notes: PT: J; TC: 0; UT: WOS:000317488400009